SAS Regression Examples - University of Michigan



SAS Regression Examples

/***********************************************

SAS EXAMPLE -- SIMPLE REGRESSION

MULTIPLE REGRESSION

COLLINEARITY DIAGNOSTICS

FILENAME: regress1.sas

************************************************/

OPTIONS NODATE FORMDLIM=" " PAGENO=1;

TITLE;

LIBNAME LABDATA "C:\TEMP\LABDATA";

DATA LABDATA.WERNER;

INFILE "c:\temp\labdata\werner2.dat";

INPUT ID $ 1-4 AGE 5-8 HT 9-12 WT 13-16

PILL 17-20 CHOL 21-24 ALB 25-28 1

CALC 29-32 1 URIC 33-36 1;

IF HT = 999 THEN HT = .;

IF WT = 999 THEN WT = .;

IF CHOL = 600 THEN CHOL = .;

IF ALB = 99 THEN ALB = .;

IF CALC = 99 THEN CALC = .;

IF URIC = 99 THEN URIC = .;

WTALB=WT+ALB;

/*CREATE AGEGRP AND AGE INDICATOR DUMMY VARIABLES*/

IF AGE NOT = . THEN DO;

IF AGE < 25 THEN AGEGRP = 1;

IF AGE >= 25 AND AGE < 32 THEN AGEGRP = 2;

IF AGE >= 32 AND AGE < 42 THEN AGEGRP = 3;

IF AGE >= 42 THEN AGEGRP = 4;

AGEDUM1 = (AGEGRP = 1);

AGEDUM2 = (AGEGRP = 2);

AGEDUM3 = (AGEGRP = 3);

AGEDUM4 = (AGEGRP = 4);

END;

RUN;

/*******************************************************

CHECK DATA

********************************************************/

OPTIONS NOLABEL;

PROC MEANS DATA=LABDATA.WERNER;

TITLE "DESCRIPTIVE STATISTICS";

RUN;

/***********************************************************

CORRELATION

************************************************************/

PROC CORR DATA=LABDATA.WERNER;

VAR AGE CHOL;

RUN;

/***********************************************************

SIMPLE SCATTER PLOT, OR DO THIS IN INSIGHT

************************************************************/

GOPTIONS RESET=ALL;

GOPTIONS DEVICE=WIN TARGET=WINPRTM;

SYMBOL1 COLOR=BLACK VALUE=DOT INTERPOL=RL;

PROC GPLOT;

PLOT CHOL*AGE;

TITLE "SCATTER PLOT WITH REGRESSION LINE";

RUN;

/***********************************************************

SIMPLE REGRESSION

************************************************************/

OPTIONS LABEL;

PROC REG DATA=LABDATA.WERNER;

MODEL CHOL=AGE;

TITLE "SIMPLE REGRESSION WITH NO OPTIONS";

RUN; QUIT;

PROC REG DATA=LABDATA.WERNER;

MODEL CHOL=AGE / P R CLI CLM;

PLOT (RSTUDENT.) * (PREDICTED. AGE OBS.);

OUTPUT OUT=OUTREG1 P=PREDICT1 R=RESID1 RSTUDENT=RSTUD1

LCL=LCL1 UCL=UCL1 LCLM=LCLM1 UCLM=UCLM1;

TITLE "SIMPLE REGRESSION WITH DIAGNOSTIC PLOTS";

TITLE2 "AND OUTPUT DATA SET TO GET RESIDUALS";

RUN;QUIT;

PROC PRINT DATA=OUTREG1(OBS=10) LABEL;

VAR ID PILL AGE CHOL PREDICT1 RESID1 RSTUD1 LCL1 UCL1 LCLM1 UCLM1;

TITLE "PARTIAL LISTING OF OUTPUT DATA SET";

TITLE2 "TO CHECK RESIDUALS AND PREDICTED VALUES";

RUN;

PROC UNIVARIATE DATA=OUTREG1 PLOT NORMAL;

VAR RSTUD1;

HISTOGRAM;

QQPLOT / NORMAL(MU=EST SIGMA=EST);

TITLE "CHECKING RESIDUALS FROM FIRST REGRESSION";

TITLE2 "FOR NORMALITY";

RUN;

/***********************************************

MULTIPLE REGRESSION--CHECK FOR COLLINEARITY

***********************************************/

/*FIRST, EXAMINE CORRELATION MATRIX*/

PROC CORR DATA=LABDATA.WERNER NOMISS;

VAR CHOL AGE CALC URIC ALB WT WTALB;

TITLE "PEARSON CORRELATION MATRIX";

RUN;

/*TO GET SCATTER-PLOT MATRIX, YOU CAN USE INSIGHT:

ANALYSIS > MULTIVARIATE(YX).

CHOOSE CHOL CALC URIC AGE AS Y

CLICK ON THE OUTPUT BUTTON AND CHOOSE > SCATTER-PLOT MATRIX*/

PROC REG DATA=LABDATA.WERNER;

MODEL CHOL = AGE CALC URIC ALB WT / STB TOL VIF COLLIN;

PLOT RESIDUAL.*PREDICTED.;

OUTPUT OUT=OUTREG2 P=PREDICT2 R=RESID2 RSTUDENT=RSTUD2;

TITLE "MULTIPLE REGRESSION ANALYSIS";

TITLE2 "WITH RESIDUAL DIAGNOSTICS";

RUN;QUIT;

PROC UNIVARIATE DATA=OUTREG2 PLOT NORMAL;

VAR RESID2;

HISTOGRAM;

QQPLOT / NORMAL(MU=EST SIGMA=EST);

TITLE "CHECKING RESIDUALS FROM MULTIPLE REGRESSION";

RUN;

PROC PRINT DATA=OUTREG2;

WHERE RESID2 50;

MODEL CHOL = AGE CALC URIC ALB WT / STB TOL VIF COLLIN;

PLOT RESIDUAL.*PREDICTED.;

OUTPUT OUT=OUTREG3 P=PREDICT3 R=RESID3 RSTUDENT=RSTUD3;

TITLE "MULTIPLE REGRESSION ANALYSIS";

TITLE2 "WITH RESIDUAL DIAGNOSTICS";

TITLE3 "REMOVE OUTLIER FOR CHOLESTEROL";

RUN;QUIT;

PROC UNIVARIATE DATA=OUTREG3 PLOT NORMAL;

VAR RESID3;

HISTOGRAM;

QQPLOT / NORMAL(MU=EST SIGMA=EST);

TITLE "CHECKING RESIDUALS FROM MULTIPLE REGRESSION";

TITLE2 "WITH OUTLIER REMOVED";

RUN;

/*COLLINEARITY DIAGNOSTICS*/

PROC REG DATA=LABDATA.WERNER;

MODEL CHOL = AGE CALC URIC ALB WT WTALB/ STB TOL VIF COLLIN;

TITLE "MULTIPLE REGRESSION ANALYSIS";

TITLE2 "WITH COLLINEARITY";

RUN;QUIT;

PROC REG DATA=LABDATA.WERNER;

MODEL CHOL = AGE CALC URIC WT WTALB/ STB TOL VIF COLLIN;

TITLE "MULTIPLE REGRESSION ANALYSIS";

TITLE2 "REMOVE ALB, BUT STILL HAS COLLINEARITY";

RUN;QUIT;

DESCRIPTIVE STATISTICS

The MEANS Procedure

Variable N Mean Std Dev Minimum Maximum

ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ

AGE 188 33.8191489 10.1126942 19.0000000 55.0000000

HT 186 64.5107527 2.4850673 57.0000000 71.0000000

WT 186 131.6720430 20.6605767 94.0000000 215.0000000

PILL 188 1.5000000 0.5013351 1.0000000 2.0000000

CHOL 187 235.1550802 44.5706219 50.0000000 390.0000000

ALB 186 4.1112903 0.3579694 3.2000000 5.0000000

CALC 185 9.9621622 0.4795556 8.6000000 11.1000000

URIC 187 4.7705882 1.1572312 2.2000000 9.9000000

WTALB 184 135.7978261 20.6557047 98.1000000 219.3000000

AGEGRP 188 2.5425532 1.1106186 1.0000000 4.0000000

AGEDUM1 188 0.2340426 0.4245295 0 1.0000000

AGEDUM2 188 0.2446809 0.4310457 0 1.0000000

AGEDUM3 188 0.2659574 0.4430215 0 1.0000000

AGEDUM4 188 0.2553191 0.4372048 0 1.0000000

ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ

The CORR Procedure

2 Variables: AGE CHOL

Simple Statistics

Variable N Mean Std Dev Sum Minimum Maximum

AGE 188 33.81915 10.11269 6358 19.00000 55.00000

CHOL 187 235.15508 44.57062 43974 50.00000 390.00000

Pearson Correlation Coefficients

Prob > |r| under H0: Rho=0

Number of Observations

AGE CHOL

AGE 1.00000 0.36923

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download